Apparatus for washing and degreasing



1969 c. T. ASHWORTH APPARATUS FOR WASHING AND DEGREASING Sheet 4 "of 5 Filed May 8, 1964 Adz/70K. C -mfiervk IQSHH ATII zuw Feb. 11, 1969 c. T. ASHWORTH 3,425,373

- APPARATUS FOR WASHING AND DEGREASING Filed May 8, 1964 Sheet 2 of 5 e 1969 c. T. ASHWORTH APPARATUS FOR WA5HING AND DEGREASING Filed May 8, 1964 Feb.ll,l969

Filed May 8, 1964 c. T. ASHWORTH 3,426,378

APPARATUS FOR WASHING AND DEGREASING' Sheet 4 of 5 /Y ran 70!.

014 @mk MK 7 Feb. 11, 1969 c. T. ASHWORTH APPARATUS FOR WASHING AND DEGREASING Filed May 8, 1964 Sheet F lG-.

United States Patent 3,426,378 APPARATUS FQR WASHING AND DEGREASING Colin Trevor Ashworth, Henley-in-Arden, Solihull, England, assignor to Abrasive Developments Limited, Solihull, England, a British company Filed May 3, 1964, Ser. No. 365,879 Claims priority, application Great Britain, May 15, 1963, 19,234/63; Nov. 7, 1963, 43,943/ 63 US. Cl. 153 Int. Cl. BtlSb 3/02; Bells 3/ 00 2 Claims ABSTRACT OF THE DISCLOSURE This invention relates to apparatus for washing and/ or degreasing. The invention is applicable with particular advantage to the cleaning of motor vehicles and railway trains and also for the degreasing of strip metal and fabricated parts. The invention is not, however, limited to such uses.

The present usual method of cleaning railway trains or cars involves the use of one or more large rotating mops or flails. These mops or fiails are generally made of leather or camelhair and are brought into contact with the parts to be cleaned when the :motor vehicle or train is stationary. The method further includes the spraying of water containing detergent either on to the fiails or to the parts to be cleaned before they are contacted by the flails. After the vehicle or train has been subjected to the washing action of the flails, the vehicle or train is rinsed off with water so that the detergent solution is removed. The above-described method has several disadvantages. One such disadvantage is that the tfiails or mops are not able to clean parts having awkward contours nor do they clean in the crevices on the vehicle or train. A second disadvantage is that the flail-s cannot be positioned to clean the ends of the vehicle or a train or a carriage thereof. A third disadvantage is that dirt becomes entrained in the flails or mops and the latter drag the dirt over the surface of the vehicle or train to be washed thereby damaging the paint where such surface is painted. A further disadvantage is that the flails or mops wear out and have to be replaced at regular intervals which is expensive. A still further disadvantage is the lack of close control over the mops or flails due to their large size.

Finally, the train or motor vehicle has to be stationary while it is in contact with the mops or flails and this makes the cleaning operation a very slow job.

The object of the invention is to provide apparatus for applying washing or degreasing solution to an article which overcomes or reduces the disadvantages above described in relation to the flail or mop system of washing.

According to the invention there is provided apparatus for cleaning an article comprising a supply of flowable cleaning substance; centrifugal throwing wheel means arranged to cause the substance to impinge on the article, each wheel of said means comprising two spaced parallel plates arranged transverse to the axis of rotation of the wheel and a plurality of blades extending axially of the wheel across the whole distance between the plates and extending centrifugally of the wheel from adjacent the centre thereof to adjacent to the periphery thereof, the

3,426,378 Patented Feb. 11, 1969 centre line of each blade lagging, having regard to the direction of rotation of the wheel, a radius of the wheel which passes through the inner end of the blade; means to supply said substance to a central portion of each said wheel, a tank for collecting the used substance after it has impinged on the article together with any contained dirt removed from the article; centrifugal separator means; pump means to draw the used substance from the tank and pass it to the separator means; means for conveying a first, clean fraction of the substance to the throwing wheel means for reuse; and means for conveying a second fraction of the substance containing the dirt to Waste.

The apparatus may be used either with a liquid cleaning substance or with a cleaning substance which contains solid particles. In the latter case the centrifugal separator means is arranged to provide three fractions, a first fraction containing substantially all of the said particles and being delivered to said throwing wheel means, a second fraction containing said dirt and being discharged to waste and a third fraction containing substantially no such particles and being delivered to rinse means arranged to rinse the article after treatment with the particles.

The advantages which are to be obtained by using the invention described above as compared with the iflail or mop method of washing are as follows:

(a) Due to the speed at which the liquid impinges on the article it is possible to dislodge the dirt quickly to obtain a clean surface.

(b) Since there is no physical contact between the article to be cleaned and members such as brushes or flails, there is no danger of the article being scratched or otherwise damaged.

(-c) It is simple to direct the throwing wheel either permanently or adjustably during operation so that awkward contours can be cleaned and so that, for example, the end surfaces of railway carriages can be cleaned.

(d) The sheet of liquid which leaves the periphery of the wheel and impinges on the article is capable of of entering all the crevices which are open to the outer surface of the article and of cleaning such crevices.

(e) Running costs of apparatus embodying the invention are low since there are no flails or mops to be replaced at periodic intervals.

(f) The method may be used with washing or degreasing liquid containing solid particles or not as desired, thus the method can be adapted to the surface to be cleaned. The apparatus can also easily be adapted to work either with or without solid particles.

The invention will now be described in detail by way of example with reference to the accompanying drawings which show a cleaning installation for railway rolling stock and in which:

FIGURE 1 is a longitudinal sectional elevation of the apparatus on the line 1"-1 of FIGURE 3;

FIGURE 2 is a sectional plan of the apparatus on the line 22 of FIGURE 3 with parts broken away for clarity;

FIGURE 3 is a vertical sectional elevation on the line 3-3 of FIGURE 2;

FIGURE 4 is a perspective view of an enclosure showing the mounting of a throwing wheel and its driving motor;

FIGURE 5 is a perspective view, partly in section, of a throwing wheel used in the apparatus; and

FIGURE 6 is a schematic view showing the pipe connections of the apparatus.

Referring first to FIIGURES 1, 2 and 3, the apparatus comprises a length of railway track 10 on which the railway train or carriage to be washed is traversed through the apparatus.'The apparatus comprises a wetting section 11, a washing and degreasing section 12, a pre-rinsing section 13 and a clean rinsing section -14. The train passes through all these sections in turn.

The wetting section comprises two gantries 15 arranged one either side of the track and provided with nozzles 16 which direct clean water at the sides of the train. The water drains into a surnp 17 and passes through a drain 18 to waste.

The washing and degreasing sections 12 and the prerinse section 13 are housed within a light covering structure comprising side walls 19, end walls 20 and a roof 21. The walls are supported by uprights 22.

Within the covering structure is a gantry 23 whose main purpose is to support four centrifugal throwing wheels which direct washing or degreasing liquid onto the train. The gantry comprises, on each side of the track, three pairs of uprights 24 which are cross-braced by horizontal members 25. The uprights 24 nearest to the track v10 are slightly longer than the other uprights 24 and inclined cross beams 26 are secured to the upper ends of the upright 24 and are joined centrally with flanges 27.

Extending longitudinally of the gantry are protective means to prevent the washing or degreasing liquid from impinging on the top of the roof or on the wheels of a railway carriage such as is shown in phantom lines at 28 in FIGURE 3. These protective means comprise rubber or like strips 29 which are supported from upper and lower rails 30 and 31 respectively so that the rubber strips engage the railway carriage at the points shown. A similar arrangement is provided on each side of the gantry. The rails 30 and 31 are held by transverse members 32 and 33 respectivley secured to the uprights 24.

Referring now to FIGURE 1, each side of the gantry is provided with two enclosures each of which contains a centrifugal throwing wheel and its driving motor. One such enclosure is indicated at 34 and the other enclosure at 35. The enclosure 34 is arranged so that it is at a higher level than the enclosure 35 and also, referring to FIGURE 3, each enclosure '34 is inclined to the vertical as shown whereas each enclosure 35 is arranged vertically.

Each enclosure contains a centrifugal throwing wheel and a driving motor therefor and is shown in detail in FIGURE 4. Referring to that figure, the enclosure comprises an open frame made up of four vertical members 36 joined by front members 37, rear members 38 and side members 39. Extending between each pair of front and rear members 37 and 38 are a pair of rods, the upper rods of which are indicated at 40 and the lower rods at 41. The rods pass through collars, one of which is indicated at 42 secured to the front and rear members and the ends of the rods are threaded and provided with securing nuts 43. The major expanse of each rod 40 and 41 is plain and slidable thereon are lugs which support an internal framework for movement parallel to the side members 39.

The framework comprises a top plate 44 and a bottom plate 45. The top plate carries lugs 46 which slide on the rods 40 and the bottom plate carries similar lugs, not shown, which slide on the rods 41. The plates 44, 45 are joined by four vertical rods 47 at the corners thereof and slidable vertically on these rods is a box-like structure indicated generally at 48. The box-like structure 48 comprises an upper plate 49 and a lower plate 50 which are connected by channel members 51 and 52. The channel members are in turn connected by upper and lower horizontal channel members 53 and 54 respectively.

The box-like structure 48 is movable vertically relative to the plates 44, 45 by means of a threaded shaft 55 which is received in an internally threaded collar 56 in the upper plate 49. Means not shown comprising a hand wheel and chain drive are provided to rotate the shaft 55.

Similarly, the framework consisting of the plates 44, 45 and the vertical rods 47 is movable in directions parallel to the side members 39 by means of a threaded shaft 57 which is also rotated by a hand wheel (not shown) by means of a chain drive.

Mounted in the box-like structure 48 is a centrifugal throwing wheel which is mounted in a shroud 58 having a divergent portion terminating in a mouth 59. The shroud with its enclosed throwing wheel is mounted on bearings 60 so as to be pivotable about a vertical axis. Secured to the shroud 58 is a driving motor 61 which rests upon a bracket 62 secured to the plate 58. An electric motor 63 and reduction drive 64 are provided to rotate the shroud 58 and the motor 61 about its vertical axis, the motor 61 being supported by the bracket 62 during such movement.

The construction of the throwing wheel mounted in each shroud 58 is shown in FIGURE 5. The throwing wheel comprises two spaced parallel plates 65 mounted on a hollow shaft 66. The internal faces of the plates 65 are aligned with discs 67 of neoprene or rubber which have retroverted outer edges 68 to embrace the outer periphery of the disc. Mounted between the discs 67 are a plurality of rubber-covered blades 69 each of which is held in position by three pins 70 passing through the plates 65 and the blades. The blades are not truly radial but the centre line of each blade is inclined to a radius of the hollow shaft 66 by an angle of 15 and the centre line of the blade lags the radius when considered in the direction of rotation of the centrifugal throwing wheel.

Each blade is rounded on its leading face adjacent its inner and outer ends. Thus, as indicated in FIGURE 5, the outer end of a blade is rounded at 71 to facilitate the discharge of liquid from the spaces between the blades Whereas the inner end of each blade is rounded as at 72 to facilitate the entry of liquid into the space between the blades. One of the plates 65 is provided with an entry 73 through which liquid is delivered to the wheel. The shaft 66 is provided with a thrower ring 74 to prevent liquid passing along the external surface of the shaft to the bearings of its driving motor 61.

As mentioned above, each of the enclosures 34 and 35 contains a structure described with reference to FIGURE 4 and each shroud 58 contains a throwing wheel as described with reference to FIGURE 5. In order to prevent liquid discharged by the throwing wheel from being deflected by the railway carriage onto the mechanism shown in FIGURE 4, the mouth 59 of each shroud is connected to the front horizontal members 37 of the enclosure and the front vertical members 36 of the enclosure by means of flexible diaphragms. These are shown in FIGURE 1 for the enclosure 35 thus there is a flexible diaphragm 75 between the upper horizontal member 37 and the top of the shroud mouth, diaphragms 76 between the vertical edges of the shroud mouth and the vertical members 36 and a further diaphragm, not shown, between the lowest front member 37 and the bottom of the shroud month. These diaphragms are conveniently formed of rubber or the like and are provided with bellows folds so that the shroud can be adjusted within the enclosure by mechanism described in FIGURE 4 while still maintaining the enclosure sealed against the ingress of liquid from the chamber.

The apparatus further comprises a sump 77 best seen in FIGURES 1 and 3 which leads by means of a conduit 78 to a main tank 79. Mounted above the tank are two hoppers 80 and 81, the hopper 80 being arranged to contain detergent material and the hopper 81 being arranged to contain solid particles such, for example, as ballotini made from lead or soda glass. The hopper 81 is provided with a screw conveyor 82 shown in FIGURE 3 which discharges the material into a mixing chamber 83. The hopper 80 is provided with a valve 84 which allows detergent to be discharged into the mixing chamber 83. A main water pipe 85 also leads into the mixing chamber 83 and is provided with a control valve 86. A stirrer 87 is mounted in the mixing chamber and the latter discharges through a valve 88 into a funnel 89 leading into the main tank 79.

The liquid and particles delivered to the main tank 79 are heated by immersion heaters 90 and the liquid and particles are withdrawn from the bottom of the tank by means of two pumps 91. The pumps may conveniently be of a type described in British patent specification No. 840,671 in the name of Abrasive Developments Limited and published on July 6, 1960.

The liquid and particles drawn by the pumps 91 are passed to two centrifugal separators 92, each centrifugal separator being supplied by one of the pumps. Each separator may be of the type described in US. Patent No. 3,298,137 of S. I. Ashworth filed Sept. 2, 1964. Each centrifugal separator supplies the throwing wheels on one side of the gantry with liquid and particles as will hereinafter he described. Each centrifugal separator also supplies a pre-rinse pipe '93 of which there are two located one on each side of the track. One of the separators 92 supplies one of the rinse pipes 93 and the other separator supplies the other rinse pipe. As will be seen from FIG- URE 1, the rinse pipes are inclined to the vertical so that the upper end of each pipe lags relative to its lower end in relation to the direction of movement of a train through the apparatus, i.e. from left to right in FIGURE 1.

Returning now to FIGURE 1, the apparatus also includes a settling tank 94 and a grease tank 95. Liquid from the main tank 79 overflows continuously through a pipe 96 into the settling tank 94. The grease and dirt in the liquid rise to the top and overflows into the grease tank 95. From the grease tank 95 the dirt and grease is pumped by means of a pump 97 up a pipe 98 shown in FIGURE 3 into a mobile grease container 99 which can be moved to dispose of the grease when full.

The liquid and solid particles falling to the bottom of the settling tank 94 are removed by means of a pump 100 and are returned to the tank 79 below the upper surface of the liquid therein. Such apparatus for degreasing is fully described in US. Patent No. 3,372,704 filed Aug. 3 1, 1964 by Norman Ives Ashworth. I

To the right of the washing and degreasing section 12 and the pre-rinse section 13 is the clean rinse section 14 which consists of two gantries 101 mounted on opposite sides of the track and supplied with main water through pipes 102. The rinse water drains into a sump 103 and is discharged to waste. If desired, further clean water rinses may be provided after the clean rinse section 14.

The operation of the apparatus will now be described and reference will be made particularly to FIGURE 6 which shows the pipe lines connecting the various parts herein before described. The operation is preferably started by means of a switch, not shown, operated as the train approaches the apparatus, the switch being operative to set in train a series of events. Mains water is supplied to the pre-wash gantries and the train is thus wetted before entering the washing and degreasing section.

The switch also operates the valve 84 to allow a predetermined amount of detergent to flow into the mixing chamber 83 and operates the screw conveyor 82 to deliver a predetermined quantity of ballotini from the hopper 81 into the mixing chamber 83. The sequence also includes the opening of the valve 86 to allow water from the mains to flow into the mixing chamber and to rotate the mixing paddle 87 to mix the components and to discharge them through the valve 88 into the tank 79. The mixture is heated in the tank 79 by means of the immersion heaters 90 which are turned on by the switch, and the mixture is then drawn from the tank by the two pumps 91. The mixture is passed along pipe lines 104 through valves 105 to the centrifugal separators 92. (By closing the valves 105 and opening the valve 105a one pump 91 may be used to empty the tank 79.) The centrifugal separators act to separate the mixture of liquid and particles in the pipes lines 104 into three fractions. A first fraction is passed from each separator 92 along pipe lines 106 and 107 to the throwing wheels located in the upper and lower enclosures 34 and 35 respectively. This fraction consists of substantially all of the solid particles together with entrained liquid. The second fraction passes along pipe lines 108 to the pre-rinse pipes 93. This fraction comprises substantially the whole of the remainder of the liquid but with substantially no solid particles. Finally, the third fraction is discharged along pipe lines 109 and consists of a small amount of the liquid containing very fine particles which may be dirt which has not settled in the settling tank 94 and shattered ballotini which are no longer of value.

The throwing wheels are rotated and discharge the hot {washing or degreasing liquid with its entrained particles against the train as it passes through the gantry. The liquid and particles are drained off the train into the sum-p 77 .and are returned through the conduit 78 to the tank 79. As the train progresses through the apparatus, it comes opposite to the pre-rinse pipes 93. These spray the sides of the train with detergent which is substantially free from solid particles. The detergent liquid discharged from the pre-rinse pipes 93 has the eflfect of washing off from the train any solid particles which may be left adhering thereto after the train has passed through the washing and degreasing section 12. Due to the slope of the pipes 93, the upper part of the train will be treated first followed by the lower part of the train as this comes into line with the lower ends of the pipes 93. The detergent solution draining off the pre-rinse section also enters the sump 77 and is returned to the main tank 79 through the conduit 78.

The train then passes into the clean rinse section 14 where it is treated with clean Water discharged from the gantries 101. As mentioned above, further clean water rinses may be provided to treat the train after it has passed between the gantries 101 if such further rinse is desired.

Returning now to the washing and degreasing section 12, the washing or degreasing liquid and the particles entrained therein are discharged from the peripheries of the throwing wheels at very high linear velocities of between 10,000 and 20,000 feet per minute. The throwing wheels in the enclosures 34 clean the upper parts of the train as will clearly be seen from consideration of FIGURE 3, and the inclination of such enclosures helps to direct the liquid downwardly on to the upper part of the train. The throwing wheels in the enclosures 35, on the other hand, clean the lower part of the train. The upper part of the train is cleaned first as it comes beneath the gantry since the upper enclosures 34 are at the lefthand end of the gantry and the lower enclosures 35 are at the right-hand end of the gantry. Liquid and particles discharged by the throwing wheels dislodge the dirt from the train and drain down into the sump 77 carrying the dirt with them. Any liquid or dirt which bounces off the side of the train is prevented from entering into the mechanism shown in FIGURE 4 by means of the flexible diaphragms and 76.

The throwing wheels in the enclosures 34 and 35 may be controlled about their vertical pivots from an electrical control panel 110 shown in FIGURE 2. This control panel is on a elevated platform 110a so that the operator can watch the train passing through and can control the various throwing wheels accordingly so as to be able to clean the ends of the train or the ends of discrete carriages forming the train. The vertical adjustments of the throwing wheels and the adjustment-s towards and away from the chamber are made by hand wheels as above described and will not normally be made during operation of the apparatus. The adjustment can be made before operation of the apparatus so that the latter is adjusted for a train or vehicle of particular size which is being passed through the gantry.

The solid particles may, as mentioned above, be ballotini made of lead or soda glass. Alternatively, they may be particles of a synthetic resin, preferably a resin which does not shatter when the particles impinge upon the train. Suitable synthetic resins are cellulose acetate, highimpact polystyrene and acrylic resins. The particles may be of any convenient size up to 30 microns. Alternatively, particles of a textile or fibrous material may be used, such as felt which may be present either in pieces or as a powder. In any event the concentration of solid particles may be between one quarter and two pounds per gallon of liquid. Any convenient detergent may be used depending upon the type of dirt or grease to be removed from the train. One suitable detergent is a solution of sodium phosphate made up to a concentration of approximately N/40. The detergent may also contain a wetting agent to assist its function.

The size of each throwing wheel will depend upon the article to be cleaned or degreased, but generally the wheel will have a diameter of between 6 and 24 inches and will be rotated at a speed between approximately 600 r.p.m. and 2,900 r.lp.rn.

Various modifications may be made to the apparatus shown in the drawings. Thus, the clean rinse section may comprise two vertical, slit-like nozzles arranged one at each side of the train to spray the train with a large volume of water at low pressure so that substantially no aeration of water takes place. Alternatively, the rinsing could be carried out with throwing wheels of the same general construction as that shown in FIGURE -such a rinse might be applicable in certain applications. Whatever type of clean water rinsing section is provided, an anti-foaming agent may be added to the rinsing Water to prevent foaming thereof.

Where the apparatus is to be used for cleaning motor vehicles, then it may be sufficient to have merely one throwing wheel on each side of the chamber through which the motor vehicle is traversed to perform the washing and degreasing action. This will, of course, be followed by rinsing.

If desired, the rinse water may itself be recirculated and may be clarified either by passing it through centrifugal separators or by passing it through a series of cloth filter units. Such filter units may be arranged in parallel so that some of the units may be in use while the remainder are being cleaned. Alternatively, the cleaning of the liquid may be in the form of a continuous filter through which the liquid is drawn or the sump may include a paddle or other means to draw off the top portion of the liquid lying in the sump intermittently to remove the upper layer of such liquid which will consist of grease and dirt. The paddle may be associated with a weir so that the contaminated top layer of liquid flows over the weir.

In another arrangement, the invention provides a hand tool in the form of a throwing wheel mounted within a casing for rotation and being driven by means of compressed air or a flexible drive. A flexible lpipe delivers liquid to the centre of the wheel and the casing is provided with an opening to allow the liquid tobe delivered from a portion of the periphery of the wheel onto the article to be cleaned.

The invention is also applicable to the cleaning of strip metal and fabricated parts. In the case of strip metal, this is produced with a greasy or oily film thereon which has to be removed. The present arrangement is to pass the strip through a degreasing tank in which each portion of the strip remains sufiiciently to be degreased by the solution in the tank. With fabricated components suchas metal panels for refrigerators for example, these are now degreased by being immersed in a tank of degreasing' solution.

The invention can be used to degrease both strip and components by causing these to pass through a tunnel or chamber which has a series of throwing wheels in the sides thereof to cause Washing or degreasing liquid to impinge upon both sides of the article being degreased.

This method has the advantage that it is continuous and extremely efficient.

It will be seen that the invention provides a simple, eificient and comparatively cheap method and apparatus for cleaning vehicles. In particular, it has been found extremely useful for cleaning railway rolling stock where conventional methods have not been at all successful.

What I claim then is:

1. Apparatus for cleaning an article comprising a supply of fiowable cleaning substance; centrifugal throwing rwheel means arranged to cause the substance to impinge on the article; said wheel means comprising two spaced parallel plates arranged transverse to the axis of rotation of the wheel and a plurality of substantially straight blades having rounded inner and outer ends and extending axially of the wheel across the whole distance between the plates and extending centrifugally of the wheel from adjacent to :but spaced from the center thereof at the blade inner ends to adjacent the periphery thereof at the blade outer ends, the center line of each blade being inclined to a radius of the wheel and intersecting the radius at a point adjacent to but spaced from the center of the wheel, said center line lying on the lagging side of the radius having regard to the direction of rotation of the Wheel; means to supply said substance to a central portion of each said wheel; means for collecting the used substance after it has impinged on the article together with any contained dirt removed from the article; centrifugal separator means; pump means to draw the used su-bstance from the tank and pass it to the separator means; means for conveying a first, cleaned fraction of the substance from the separator means to the throwing wheel means for reuse; and means for conveying a second fraction of the substance from the separator means and containing the dirt to waste.

2. Apparatus according to claim 1 wherein the cleaning substance comprises a mixture of liquid and solid particles and wherein the centrifugal separator means is arranged to provide three fractions, a first fraction containing substantially all of the said solid particles which passes along said first mentioned conveying means to the throwing wheel means; a second fraction containing the dirt and which passes along said second conveying means to waste; and a third fraction containing substantially no solid particles; the apparatus including rinse means and third conveying means extending between the rinse means and the centrifugal separator to convey said third fraction from the separator means to the rinse means.

References Cited UNITED STATES PATENTS 847,270 3/1907 Wise. 1,892,950 1/1933 Houpt 134-10 1,907,411 5/1933 Timoney. 1,934,494 11/1933 Gillespie 134-7 1,977,386 10/1934 Holes. 2,250,500 7/1941 Rosenberger 51-318 XR 2,426,072 8/ 1947 Wall et 8.1. 2,429,742 10/ 1947 Barnes 51-321 XR 2,605,596 8/1952 Uhri 51-321 2,632,980 3/ 1953 Ransohotf 51-320 XR 2,669,810 2/1954 Carlson et al. 51-320 XR 2,671,241 3/1954 Starner 134-7 XR 2,763,964 9/1956 Luce 51-11 XR 3,142,590 7/ 1964 Hergonson 134-7 FOREIGN PATENTS 874,720 8/1961 Great Britain. 719,501 11/1931 France.

MORRIS O. WOLK, Primary Examiner. JOSEPH T. ZATARGA, Assistant Examiner.

US. Cl. X.R. 134-7, 32. 

